RSpec boot times vs smaller test frameworks.

bacon_example.rb

$:.unshift(File.expand_path('..', __FILE__))
require 'bowling'

describe Bowling, "#score" do
  it "returns 0 for all gutter game" do
    bowling = Bowling.new
    20.times { bowling.hit(0) }
    bowling.score.should == 0
  end
end

bowling.rb

class Bowling
  def hit(pins)
  end

  def score
    0
  end
end

peck_example.rb

$:.unshift(File.expand_path('..', __FILE__))
require 'bowling'

describe Bowling, "#score" do
  it "returns 0 for all gutter game" do
    bowling = Bowling.new
    20.times { bowling.hit(0) }
    bowling.score.should == 0
  end
end

Results

~/t/rspec-vs-small » ruby -v
ruby 1.9.3p385 (2013-02-06 revision 39114) [x86_64-darwin12.2.0]

~/t/rspec-vs-small » gem install rspec peck bacon
Successfully installed rspec-2.14.1
Successfully installed peck-0.3.0
Successfully installed bacon-1.2.0
3 gems installed

~/t/rspec-vs-small » ruby time.rb
Bacon: 0.2515
Peck: 0.26
RSpec: 0.39749999999999996

rspec_example.rb

$:.unshift(File.expand_path('..', __FILE__))
require 'bowling'

describe Bowling, "#score" do
  it "returns 0 for all gutter game" do
    bowling = Bowling.new
    20.times { bowling.hit(0) }
    bowling.score.should eq(0)
  end
end

time.rb

require 'open3'

SAMPLE_SIZE = 20

def time(*command)
  total = 0
  SAMPLE_SIZE.times do
    _, __, stderr = Open3.popen3('time', '-p', *command)
    output = stderr.gets(nil)
    line = output.strip.split("\n")[-3]
    real = line.match(/\d\.\d\d/)[0]
    total += real.to_f
  end
  total / SAMPLE_SIZE
end

STDOUT.sync = true

print "Bacon: "
puts time('bacon', 'bacon_example.rb')

print "Peck: "
puts time('ruby', '-r', 'rubygems', '-r', 'peck/flavors/vanilla', 'peck_example.rb')

print "RSpec: "
puts time('rspec', 'rspec_example.rb')